Biology · Interaction and interdependence

C1.1 — Enzymes and metabolism

Biology · SL / HL · syllabus-mapped notes

1. C1.1.1

   Enzymes as catalysts

   Define catalyst and enzyme, and explain why cells need reactions speeded up.

2. C1.1.2

   Role of enzymes in metabolism

   Explain metabolism as a network of pathways, and why enzyme specificity gives cells control.

3. C1.1.3

   Anabolic and catabolic reactions

   Distinguish anabolism from catabolism, with examples of each.

4. C1.1.4

   Enzymes as globular proteins with an active site for catalysis

   Explain the active site, and why the enzyme's whole 3D structure matters.

5. C1.1.5

   Interactions between substrate and active site to allow induced-fit binding

   Explain induced-fit binding, and why it replaced the lock-and-key model.

6. C1.1.6

   Role of molecular motion and substrate-active site collisions in enzyme catalysis

   Explain how molecular motion brings substrate and active site together, and which partner moves.

7. C1.1.7

   Relationships between the structure of the active site, enzyme–substrate specificity and denaturation

   Explain how active site structure gives specificity, and why that makes enzymes easy to denature.

8. C1.1.8

   Effects of temperature, pH and substrate concentration on the rate of enzyme activity

   Explain the effects of temperature, pH and substrate concentration, and interpret the graphs.

9. C1.1.9

   Measurements in enzyme-catalysed reactions

   Determine reaction rates experimentally, controlling variables correctly.

10. C1.1.10

    Effect of enzymes on activation energy

    Explain how enzymes lower activation energy, and interpret the energy graphs.

11. C1.1.11

    Intracellular and extracellular enzyme-catalysed reactions

    Contrast intracellular and extracellular enzymes, with examples of each.

12. C1.1.12

    Generation of heat energy by the reactions of metabolism

    Explain why metabolism inevitably generates heat, and which animals depend on it.

13. C1.1.13

    Cyclical and linear pathways in metabolism

    Contrast linear and cyclical pathways, using glycolysis, the Krebs cycle and the Calvin cycle.

14. C1.1.14

    Allosteric sites and non-competitive inhibition

    Explain allosteric sites and how non-competitive inhibitors work.

15. C1.1.15

    Competitive inhibition as a consequence of an inhibitor binding reversibly to an active site

    Explain competitive inhibition using statins, and contrast it with non-competitive inhibition.

16. C1.1.16

    Regulation of metabolic pathways by feedback inhibition

    Explain end-product feedback inhibition, using the isoleucine pathway.

17. C1.1.17

    Mechanism-based inhibition as a consequence of chemical changes to the active site caused by the irreversible binding of an inhibitor

    Explain mechanism-based inhibition using penicillin, including how resistance arises.